Center for Functional MRI, University of California, San Diego, La Jolla, CA, USA.

5

Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, USA.

6

Veterans Affairs San Diego Healthcare System, San Diego, CA, USA.

Abstract

The significance of why a similar set of brain regions are associated with the default mode network and value-related neural processes remains to be clarified. Here, we examined i) whether brain regions exhibiting willingness-to-pay (WTP) task-related activity are intrinsically connected when the brain is at rest, ii) whether these regions overlap spatially with the default mode network, and iii) whether individual differences in choice behavior during the WTP task are reflected in functional brain connectivity at rest. Blood-oxygen-level dependent (BOLD) signal was measured by functional magnetic resonance imaging while subjects performed the WTP task and at rest with eyes open. Brain regions that tracked the value of bids during the WTP task were used as seed regions in an analysis of functional connectivity in the resting state data. The seed in the ventromedial prefrontal cortex was functionally connected to core regions of the WTP task-related network. Brain regions within the WTP task-related network, namely the ventral precuneus, ventromedial prefrontal and posterior cingulate cortex overlapped spatially with publically available maps of the default mode network. Also, those individuals with higher functional connectivity during rest between the ventromedial prefrontal cortex and the ventral striatum showed greater preference consistency during the WTP task. Thus, WTP task-related regions are an intrinsic network of the brain that corresponds spatially with the default mode network, and individual differences in functional connectivity within the WTP network at rest may reveal a priori biases in choice behavior.

Schematic diagram (left) of one trial of the WTP task and bar graphs (right) representing the percentage of trials each bid level was selected (top) and the average reaction time for each bid level (bottom). The reaction time for the zero bid is not represented in the lower graph because subjects were not required to make a response for the zero option.

Coronal brain section (left) to show the location of task related ROI in the left vStr ROI circled in red. Scatterplot (right) illustrating that individuals with higher intrinsic connectivity between the vmPFC seed and the right vStr also exhibit greater preference consistency (Spearman ρ = 0.65).